Heretofore, the use of thermal ink-jet printing has typically required utilizing specially treated paper or other print media to ensure high quality printing. A problem with employing "plain" paper, i.e., uncoated paper such as xerography or photocopy paper, bond paper and laser jet paper, has been that the ink compositions typically used in ink-jet printing, especially thermal ink-jet printing, have not provided the high quality print desired. For example, the long drying times of water-based inks typically have resulted in smearing of the ink.
Because of the problems associated with these inks, coated media have been employed. However, it remains a goal of thermal ink-jet printing to be able to print on plain, untreated media.
Attempts have been made to improve the ink compositions. However, reducing the drying time of the ink can adversely affect other properties of the ink. For example, shortened drying times can lead to crusting of the nozzles in the printhead, with consequent partial or full blockage of the nozzles. Thus, efforts continue to develop suitable ink compositions for printing on plain paper and other media.